Light Rail Systems Improve Air Pollution in Cities

Have you ever wondered if the cute light rail systems some large cities are installing actually get people out of their cars and have a positive environmental impact?

For the first time, researchers have shown that installing light rail on an existing traffic corridor not only gets people out of their cars, but reduces congestion and air pollution.

In the study, planners at the University of Utah measured impacts of a new light rail line in Salt Lake City (University Line) on an existing major thoroughfare (400/500 South). Their analysis showed that traffic near the University has fallen to levels not seen since the 1980s, even as the number of students, faculty and staff at the U has increased, and the commercial district along the corridor has expanded.

“This is the first study to document important effects of light rail transit on traffic volumes,” said Reid Ewing, professor of city and metropolitan planning at the University of Utah and lead author on the study. “Since the University TRAX line opened, there has been increased development in the 400/500 South travel corridor, yet traffic on the street has actually declined. Our calculations show that without the University TRAX line, there would be at least 9,300 more cars per day on 400/500 South, and possibly as many as 21,700 additional cars. The line avoids gridlock, as well as saves an additional 13 tons of toxic air pollutants. This is important knowledge for shaping future transportation policies.”

Andrew Gruber, executive director of the Wasatch Front Regional Council, which has been responsible for coordinating transportation planning in the Salt Lake and Ogden areas since 1973 said, “This study further demonstrates the value of public transportation in helping people reach their destinations, reduce traffic and spur economic development. The findings are significant for local governments across our region as they consider the future of transit in their community.”

The report—which validates assumptions widely used in travel demand models used in community planning—was issued recently by the National Institute for Transportation and Communities, and has been accepted for publication in the “Journal of Public Transportation” later this year. The report is available for download here.

Article by Roger Greenway.